firebird-mirror/src/qli/exe.cpp

/*
 *	PROGRAM:	JRD Command Oriented Query Language
 *	MODULE:		exe.c
 *	DESCRIPTION:	Execution phase
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../jrd/ib_stdio.h"
#include <setjmp.h>

#define REQUESTS_MAIN
#include "../jrd/gds.h"
#include "../qli/dtr.h"
#include "../qli/exe.h"
#include "../qli/all_proto.h"
#include "../qli/err_proto.h"
#include "../qli/eval_proto.h"
#include "../qli/exe_proto.h"
#include "../qli/form_proto.h"
#include "../qli/forma_proto.h"
#include "../qli/mov_proto.h"
#include "../qli/repor_proto.h"
#include "../jrd/gds_proto.h"
#include "../jrd/utl_proto.h"


#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_VFORK_H
#include <vfork.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifndef FOPEN_WRITE_TYPE
#define FOPEN_WRITE_TYPE	"w"
#endif

typedef vary VARY;

extern jmp_buf QLI_env;

extern USHORT QLI_prompt_count, QLI_reprompt;

static DSC *assignment(QLI_NOD, DSC *, QLI_NOD, QLI_NOD, PAR);
static void commit_retaining(QLI_NOD);
static int copy_blob(QLI_NOD, PAR);
static void db_error(QLI_REQ, ISC_STATUS *);
static void execute_abort(QLI_NOD);
static void execute_assignment(QLI_NOD);
static void execute_for(QLI_NOD);
static void execute_modify(QLI_NOD);
static void execute_output(QLI_NOD);
static void execute_print(QLI_NOD);
static void execute_repeat(QLI_NOD);
static void execute_store(QLI_NOD);
static void map_data(QLI_MSG);
static void print_counts(QLI_REQ);
static void set_null(QLI_MSG);
static void transaction_state(QLI_NOD, DBB);

/* definitions for SET COUNT */

#define COUNT_ITEMS	4

static SCHAR count_info[] = {
	gds_info_req_select_count,
	gds_info_req_insert_count,
	gds_info_req_update_count,
	gds_info_req_delete_count
};


void EXEC_abort(void)
{
/**************************************
 *
 *	E X E C _ a b o r t
 *
 **************************************
 *
 * Functional description
 *	An asynchrous abort has been requested.  Request that all
 *	requests be unwound and set flag.
 *
 **************************************/
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];
	QLI_REQ request;

	for (request = QLI_requests; request; request = request->req_next)
		if (request->req_handle)
			gds__unwind_request(status_vector,
								GDS_REF(request->req_handle), 0);

	QLI_abort = TRUE;
}


void EXEC_execute( QLI_NOD node)
{
/**************************************
 *
 *	E X E C _ e x e c u t e
 *
 **************************************
 *
 * Functional description
 *	Execute a node.
 *
 **************************************/
	QLI_MSG message;
	QLI_NOD *ptr;
	USHORT i;

	if (QLI_abort)
		EXEC_poll_abort();

	if (node)
		switch (node->nod_type) {
		case nod_abort:
			execute_abort(node);

		case nod_assign:
			execute_assignment(node);
			return;

		case nod_commit_retaining:
			commit_retaining(node);
			return;

		case nod_erase:
			if (message = (QLI_MSG) node->nod_arg[e_era_message])
				EXEC_send(message);
			return;

		case nod_for:
			execute_for(node);
			return;
#ifdef PYXIS
		case nod_form_for:
			FORM_display(node);
			return;

		case nod_form_update:
			FORM_update(node);
			return;
#endif
		case nod_list:
			ptr = node->nod_arg;
			for (i = 0; i < node->nod_count; i++)
				EXEC_execute(*ptr++);
			return;

		case nod_modify:
			execute_modify(node);
			return;

		case nod_output:
			execute_output(node);
			return;

		case nod_print:
			execute_print(node);
			return;

		case nod_repeat:
			execute_repeat(node);
			return;

		case nod_store:
			execute_store(node);
			return;

		case nod_if:
			if (EVAL_boolean(node->nod_arg[e_if_boolean])) {
				EXEC_execute(node->nod_arg[e_if_true]);
				return;
			}
			if (node->nod_arg[e_if_false]) {
				EXEC_execute(node->nod_arg[e_if_false]);
				return;
			}
			return;

		case nod_report_loop:
			RPT_report(node);
			return;

		default:
			BUGCHECK(33);		/* Msg33 EXEC_execute: not implemented */
		}
}


FRBRD *EXEC_open_blob( QLI_NOD node)
{
/**************************************
 *
 *	E X E C _ o p e n _ b l o b
 *
 **************************************
 *
 * Functional description
 *	Given a blob field node, open and return the blob.
 *
 **************************************/
	QLI_CTX context;
	QLI_REQ request;
	DBB dbb;
	DSC *desc;
	UCHAR bpb[20], *p;
	USHORT bpb_length;
	FRBRD *blob;
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];

	desc = EVAL_value(node);
	if (!desc)
		return FALSE;

/* Starting from the print item, work our way back to the database block */

	if (node->nod_type == nod_reference)
		node = node->nod_arg[0];

	if (node->nod_type != nod_field)
		BUGCHECK(34);			/* Msg34 print_blob: expected field node */

	context = (QLI_CTX) node->nod_arg[e_fld_context];
	request = context->ctx_request;
	dbb = request->req_database;
	blob = NULL;

/* Format blob parameter block */

	p = bpb;
	*p++ = gds_bpb_version1;
	*p++ = gds_bpb_source_type;
	*p++ = 2;
	*p++ = desc->dsc_sub_type;
	*p++ = desc->dsc_sub_type >> 8;
	*p++ = gds_bpb_target_type;
	*p++ = 1;
	*p++ = 1;

	bpb_length = p - bpb;

	if (gds__open_blob2(status_vector,
						GDS_REF(dbb->dbb_handle),
						GDS_REF(dbb->dbb_transaction),
						GDS_REF(blob),
						(GDS_QUAD*)GDS_VAL(desc->dsc_address),
						bpb_length,
						(char*) bpb)) ERRQ_database_error(dbb, status_vector);

	return blob;
}


struct file *EXEC_open_output(QLI_NOD node)
{
/**************************************
 *
 *	E X E C _ o p e n _ o u t p u t
 *
 **************************************
 *
 * Functional description
 *	Open output stream to re-direct output.
 *
 **************************************/
	IB_FILE *file;
	DSC *desc;
	TEXT filename[256], temp[64], *p, *q;
#ifndef WIN_NT
	TEXT *argv[20], **arg;
	int pair[2];
#endif
	SSHORT l;

/* Evaluate filename and copy to a null terminated string */

	desc = EVAL_value(node->nod_arg[e_out_file]);
	l = MOVQ_get_string(desc, &p, (VARY*) temp, sizeof(temp));
	q = filename;
	if (l)
		do
			*q++ = *p++;
		while (--l);
	*q = 0;

/* If output is to a file, just do it */

	if (!node->nod_arg[e_out_pipe]) {
		if (file = ib_fopen(filename, FOPEN_WRITE_TYPE))
			return (struct file *) file;

		ERRQ_print_error(42, filename, NULL, NULL, NULL, NULL);	/* Msg42 Can't open output file %s */
	}

/* Output is to a file.  Setup file and fork process */

#ifdef VMS
	IBERROR(35);				/* Msg35 output pipe is not supported on VMS */
#else

#ifdef WIN_NT
	if (file = _popen(filename, "w"))
		return (struct file *) file;
#else
	arg = argv;
	p = filename;
	while (*p) {
		*arg++ = p;
		while (*p && *p != ' ')
			p++;
		if (!*p)
			break;
		*p++ = 0;
		while (*p == ' ')
			p++;
	}
	*arg = NULL;

	if (pipe(pair) < 0)
		IBERROR(36);			/* Msg36 couldn't create pipe */

	if (!vfork()) {
		close(pair[1]);
		close(0);
		dup(pair[0]);
		close(pair[0]);
		execvp(argv[0], argv);
		ERRQ_msg_put(43, filename, NULL, NULL, NULL, NULL);	/* Msg43 Couldn't run %s */
		_exit(-1);
	}

	close(pair[0]);

	if (file = ib_fdopen(pair[1], "w"))
		return (struct file *) file;
#endif

	IBERROR(37);				/* Msg37 ib_fdopen failed */
#endif
	return NULL;
}


void EXEC_poll_abort(void)
{
/**************************************
 *
 *	E X E C _ p o l l _ a b o r t
 *
 **************************************
 *
 * Functional description
 *	Poll for abort flag (actually, most routines will check the
 *	flag before calling to save time).
 *
 **************************************/

	if (!QLI_abort)
		return;

	IBERROR(38);				/* Msg38 execution terminated by signal */
}


DSC *EXEC_receive(QLI_MSG message, PAR parameter)
{
/**************************************
 *
 *	E X E C _ r e c e i v e
 *
 **************************************
 *
 * Functional description
 *	Receive a message from a running request.
 *
 **************************************/
	QLI_REQ request;
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];

	request = message->msg_request;

	if (gds__receive(status_vector,
					 GDS_REF(request->req_handle),
					 message->msg_number,
					 message->msg_length,
					 GDS_VAL(message->msg_buffer),
					 0)) db_error(request, status_vector);

	if (!parameter)
		return NULL;

	return EVAL_parameter(parameter);
}


void EXEC_send( QLI_MSG message)
{
/**************************************
 *
 *	E X E C _ s e n d
 *
 **************************************
 *
 * Functional description
 *	Send a message to a running request.  First, however, map
 *	any data to the message.
 *
 **************************************/
	QLI_REQ request;
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];

	request = message->msg_request;

	map_data(message);
	if (gds__send(status_vector,
				  GDS_REF(request->req_handle),
				  message->msg_number,
				  message->msg_length,
				  GDS_VAL(message->msg_buffer),
				  0)) db_error(request, status_vector);
}


void EXEC_start_request( QLI_REQ request, QLI_MSG message)
{
/**************************************
 *
 *	E X E C _ s t a r t _ r e q u e s t
 *
 **************************************
 *
 * Functional description
 *	Start a request running.  If there is a message to be sent, do
 *	a start and send.
 *
 **************************************/
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];

	if (message) {
		map_data(message);
		if (!gds__start_and_send(status_vector,
								 GDS_REF(request->req_handle),
								 GDS_REF(request->req_database->
										 dbb_transaction),
								 message->msg_number, message->msg_length,
								 GDS_VAL(message->msg_buffer), 0)) return;
	}
	else
		if (!gds__start_request(status_vector,
								GDS_REF(request->req_handle),
								GDS_REF(request->req_database->
										dbb_transaction), 0)) return;

	db_error(request, status_vector);
}


void EXEC_top( QLI_NOD node)
{
/**************************************
 *
 *	E X E C _ t o p
 *
 **************************************
 *
 * Functional description
 *	Execute a node type.
 *
 **************************************/

	EXEC_execute(node);
}


static DSC *assignment(	QLI_NOD		from_node,
						DSC*	to_desc,
						QLI_NOD		validation,
						QLI_NOD		initial,
						PAR		parameter)
{
/**************************************
 *
 *	a s s i g n m e n t
 *
 **************************************
 *
 * Functional description
 *	Evaluate an expression and perform an assignment.  If something
 *	goes wrong and there was a prompt, try again.
 *
 **************************************/
	DSC *from_desc;
	UCHAR *p;
	QLI_MSG message;
	USHORT l, *missing_flag, trash;
	jmp_buf old_env;

	memcpy(old_env, QLI_env, sizeof(QLI_env));
	QLI_reprompt = FALSE;
	QLI_prompt_count = 0;
	missing_flag = &trash;

	if (parameter) {
		message = parameter->par_message;
		missing_flag =
			(USHORT *) (message->msg_buffer + parameter->par_offset);
	}

	try {

	memcpy(QLI_env, old_env, sizeof(QLI_env));
	from_desc = EVAL_value(from_node);

	if (from_desc->dsc_missing & DSC_initial) {
		from_desc = EVAL_value(initial);
	}

/* If there is a value present, do any assignment; otherwise null fill */

	if (*missing_flag = to_desc->dsc_missing = from_desc->dsc_missing) {
		p = from_desc->dsc_address;
		if (l = from_desc->dsc_length) {
			do {
				*p++ = 0;
			} while (--l);
		}
	}
	else {
		MOVQ_move(from_desc, to_desc);
	}

	if (validation && EVAL_boolean(validation) <= 0) {
		IBERROR(39);			/* Msg39 field validation error */
	}

	QLI_reprompt = FALSE;
	memcpy(QLI_env, old_env, sizeof(QLI_env));

	return from_desc;

	}	// try
	catch (const std::exception&) {
		if (QLI_abort || !QLI_prompt_count) {
			memcpy(QLI_env, old_env, sizeof(QLI_env));
			throw;
		}

		QLI_reprompt = TRUE;
		QLI_prompt_count = 0;
		return NULL;
	}
}


static void commit_retaining( QLI_NOD node)
{
/**************************************
 *
 *	c o m m i t _ r e t a i n i n g
 *
 **************************************
 *
 * Functional description
 *	Execute commit retaining statement for
 *	one or more named databases or all databases. 
 *	If there's more than one, prepare it.
 *
 **************************************/
	DBB database;
	QLI_NOD *ptr, *end;

/* If there aren't any open databases then obviously
   there isn't anything to commit. */

	if (node->nod_count == 0 && !QLI_databases)
		return;

	if (node->nod_type == nod_commit_retaining &&
		((node->nod_count > 1) ||
		 (node->nod_count == 0 && QLI_databases->dbb_next))) {
		node->nod_type = nod_prepare;
		commit_retaining(node);
		node->nod_type = nod_commit_retaining;
	}
	else if (node->nod_count == 1) {
		database = (DBB) node->nod_arg[0];
		database->dbb_flags |= DBB_prepared;
	}
	else
		QLI_databases->dbb_flags |= DBB_prepared;


	if (node->nod_count == 0) {
		for (database = QLI_databases; database;
			 database = database->dbb_next) {
			if ((node->nod_type == nod_commit_retaining)
				&& !(database->dbb_flags & DBB_prepared))
				ERRQ_msg_put(465, database->dbb_symbol->sym_string, NULL,
							 NULL, NULL, NULL);
			else if (node->nod_type == nod_prepare)
				database->dbb_flags |= DBB_prepared;
			if (database->dbb_transaction)
				transaction_state(node, database);
		}
		return;
	}

	for (ptr = node->nod_arg, end = ptr + node->nod_count; ptr < end; ptr++) {
		database = (DBB) * ptr;
		if ((node->nod_type == nod_commit_retaining) &&
			!(database->dbb_flags & DBB_prepared))
			ERRQ_msg_put(465, database->dbb_symbol->sym_string, NULL, NULL,
						 NULL, NULL);
		else if (node->nod_type == nod_prepare)
			database->dbb_flags |= DBB_prepared;
		if (database->dbb_transaction)
			transaction_state(node, database);
	}
}



static int copy_blob( QLI_NOD value, PAR parameter)
{
/**************************************
 *
 *	 c o p y _ b l o b
 *
 **************************************
 *
 * Functional description
 *	Copy a blob from one database to another.  If the blob can be
 *	successfully assigned, return FALSE and let somebody else just
 *	copy the blob ids.
 *
 **************************************/
	QLI_CTX context;
	QLI_MSG message;
	QLI_REQ from_request, to_request;
	DBB to_dbb, from_dbb;
	DSC *from_desc, *to_desc;
	FRBRD *from_blob, *to_blob;
	SLONG size, segment_count, max_segment;
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];
	USHORT bpb_length, length, buffer_length;
	UCHAR bpb[20], *p, fixed_buffer[4096], *buffer;
#ifdef PYXIS
	if (value->nod_type == nod_form_field)
		return FORM_get_blob(value, parameter);
#endif
/* If assignment isn't from a field, there isn't a blob copy, so
   do a dumb assignment. */

	if (value->nod_type != nod_field)
		return FALSE;

/* Find the sending and receiving requests.  If they are the same
   and no filtering is necessary, a simple assignment will suffice. */

	context = (QLI_CTX) value->nod_arg[e_fld_context];
	from_request = context->ctx_request;
	from_dbb = from_request->req_database;
	message = parameter->par_message;
	to_request = message->msg_request;
	to_dbb = to_request->req_database;

	from_desc = EVAL_value(value);
	to_desc = EVAL_parameter(parameter);

	if (to_dbb == from_dbb &&
		(!to_desc->dsc_sub_type ||
		 from_desc->dsc_sub_type == to_desc->dsc_sub_type)) return FALSE;

/* We've got a blob copy on our hands. */

	if (!from_desc) {
		*to_desc->dsc_address = 0;
		return TRUE;
	}

	to_blob = from_blob = NULL;

/* Format blob parameter block for the existing blob */

	p = bpb;
	*p++ = gds_bpb_version1;
	*p++ = gds_bpb_source_type;
	*p++ = 2;
	*p++ = from_desc->dsc_sub_type;
	*p++ = from_desc->dsc_sub_type >> 8;
	*p++ = gds_bpb_target_type;
	*p++ = 2;
	*p++ = to_desc->dsc_sub_type;
	*p++ = to_desc->dsc_sub_type >> 8;
	bpb_length = p - bpb;

	if (gds__create_blob(status_vector,
						 GDS_REF(to_dbb->dbb_handle),
						 GDS_REF(to_dbb->dbb_transaction),
						 GDS_REF(to_blob), (GDS__QUAD*) GDS_VAL(to_desc->dsc_address)))
		ERRQ_database_error(to_dbb, status_vector);

	if (gds__open_blob2(status_vector,
						GDS_REF(from_dbb->dbb_handle),
						GDS_REF(from_dbb->dbb_transaction),
						GDS_REF(from_blob),
						(GDS__QUAD*) GDS_VAL(from_desc->dsc_address),
						bpb_length,
						(char*) bpb)) ERRQ_database_error(from_dbb, status_vector);

	gds__blob_size(&from_blob, &size, &segment_count, &max_segment);

	if (max_segment < sizeof(fixed_buffer)) {
		buffer_length = sizeof(fixed_buffer);
		buffer = fixed_buffer;
	}
	else {
		buffer_length = max_segment;
		buffer = (UCHAR*) gds__alloc(buffer_length);
#ifdef DEBUG_GDS_ALLOC
		/* We don't care about QLI specific memory leaks for V4.0 */
		gds_alloc_flag_unfreed((void *) buffer);	/* QLI: don't care */
#endif

	}

	while (!gds__get_segment(status_vector,
							 GDS_REF(from_blob),
							 GDS_REF(length),
							 buffer_length,
							 (char*) GDS_VAL(buffer)))
			if (gds__put_segment(status_vector,
								 GDS_REF(to_blob),
								 length,
								 (char*) GDS_VAL(buffer)))
				ERRQ_database_error(to_dbb, status_vector);

	if (buffer != fixed_buffer)
		gds__free(buffer);

	if (gds__close_blob(status_vector, GDS_REF(from_blob)))
		ERRQ_database_error(from_dbb, status_vector);

	if (gds__close_blob(status_vector, GDS_REF(to_blob)))
		ERRQ_database_error(to_dbb, status_vector);

	return TRUE;
}


static void db_error( QLI_REQ request, ISC_STATUS * status_vector)
{
/**************************************
 *
 *	d b _ e r r o r
 *
 **************************************
 *
 * Functional description
 *	A database error has occurred.  Unless it was the result of
 *	an unwind, generate an error.
 *
 **************************************/

	EXEC_poll_abort();
	ERRQ_database_error(request->req_database, status_vector);
}


static void execute_abort( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ a b o r t
 *
 **************************************
 *
 * Functional description
 *	Abort a statement.
 *
 **************************************/
	USHORT l;
	UCHAR *ptr, temp[80], msg[128];

	if (node->nod_count) {
		l =
			MOVQ_get_string(EVAL_value(node->nod_arg[0]), (TEXT**) &ptr, (VARY*) temp,
							sizeof(temp));
		MOVQ_terminate((SCHAR*) ptr, (SCHAR*) msg, l, sizeof(msg));
		ERRQ_error(40, (TEXT*) msg, NULL, NULL, NULL, NULL);	/* Msg40 Request terminated by statement: %s */
	}

	IBERROR(41);				/* Msg41 Request terminated by statement */
}


static void execute_assignment( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ a s s i g n m e n t
 *
 **************************************
 *
 * Functional description
 *
 **************************************/
	QLI_NOD to, from, reference, initial;
	QLI_FLD field;
	PAR parameter;

	if (node->nod_flags & NOD_remote)
		return;

	to = node->nod_arg[e_asn_to];
	from = node->nod_arg[e_asn_from];
	initial = node->nod_arg[e_asn_initial];

	if (to->nod_type == nod_field) {
		reference = to->nod_arg[e_fld_reference];
		parameter = reference->nod_import;
		if (to->nod_desc.dsc_dtype == dtype_blob &&
			from->nod_desc.dsc_dtype == dtype_blob &&
			copy_blob(from, parameter)) return;
	}
#ifdef PYXIS
	else if (to->nod_type == nod_form_field) {
		FORM_put_field(from, to);
		return;
	}
#endif
	else
		parameter = node->nod_import;

	if (parameter)
		parameter = parameter->par_missing;

	assignment(from, EVAL_value(to),
			   node->nod_arg[e_asn_valid], initial, parameter);

/* propagate the missing flag in variable assignments */

	if (to->nod_type == nod_variable) {
		field = (QLI_FLD) to->nod_arg[e_fld_field];
		if (to->nod_desc.dsc_missing & DSC_missing)
			field->fld_flags |= FLD_missing;
		else
			field->fld_flags &= ~FLD_missing;
	}
}


static void execute_for( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ f o r
 *
 **************************************
 *
 * Functional description
 *	Execute a FOR loop.  This may require that a request get
 *	started, a message sent, and a message received for each
 *	record.  At the other end of the spectrum, there may be
 *	absolutely nothing to do.
 *
 **************************************/
	QLI_REQ request;
	QLI_MSG message;
	DSC *desc;

/* If there is a request associated  with the node, start it and possibly
   send a message along with it. */

	if (request = (QLI_REQ) node->nod_arg[e_for_request])
		EXEC_start_request(request, (QLI_MSG) node->nod_arg[e_for_send]);
	else if (message = (QLI_MSG) node->nod_arg[e_for_send])
		EXEC_send(message);

/* If there isn't a receive message, the body of the loop has been
   optimized out of existance.  So skip it. */

	if (!(message = (QLI_MSG) node->nod_arg[e_for_receive]))
		goto count;

/* Receive messages in a loop until the end of file field comes up
   true. */

	while (TRUE) {
		desc = EXEC_receive(message, (PAR) node->nod_arg[e_for_eof]);
		if (*(USHORT *) desc->dsc_address)
			break;
		EXEC_execute(node->nod_arg[e_for_statement]);
		if (request && request->req_continue)
			EXEC_send(request->req_continue);
	}

  count:
	if (QLI_count)
		print_counts(request);
}


static void execute_modify( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ m o d i f y
 *
 **************************************
 *
 * Functional description
 *	Execute a modify statement.  This probably involves sending a
 *	message to the running request and executing a sub-statement.
 *
 **************************************/
	QLI_MSG message;


	if (node->nod_flags & NOD_remote)
		return;

	if (message = (QLI_MSG) node->nod_arg[e_mod_send])
		set_null(message);

	EXEC_execute(node->nod_arg[e_mod_statement]);

	if (message)
		EXEC_send(message);
}


static void execute_output( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ o u t p u t
 *
 **************************************
 *
 * Functional description
 *	Open output stream to re-direct output.
 *
 **************************************/
	PRT print;
	jmp_buf old_env;
	jmp_buf env;

	print = (PRT) node->nod_arg[e_out_print];
	print->prt_file = EXEC_open_output(node);

/* Set up error handling */

	memcpy(old_env, QLI_env, sizeof(QLI_env));
	memcpy(QLI_env, env, sizeof(QLI_env));

	try {

/* Finally, execute the query */

	EXEC_execute(node->nod_arg[e_out_statement]);
	memcpy(QLI_env, old_env, sizeof(QLI_env));
	ib_fclose((IB_FILE *) print->prt_file);

	}	// try
	catch (const std::exception&) {
		if (print->prt_file) {
			ib_fclose((IB_FILE *) print->prt_file);
		}
		memcpy(QLI_env, old_env, sizeof(QLI_env));
		throw;
	}
}


static void execute_print( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ p r i n t
 *
 **************************************
 *
 * Functional description
 *	Execute a print statement.  Since the loop has been factored
 *	out, this should be easy.
 *
 **************************************/

	if (node->nod_arg[e_prt_header]) {
		FMT_put((TEXT*) node->nod_arg[e_prt_header], (PRT) node->nod_arg[e_prt_output]);
		node->nod_arg[e_prt_header] = NULL;
	}

	FMT_print(node->nod_arg[e_prt_list], (PRT) node->nod_arg[e_prt_output]);
}


static void execute_repeat( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ r e p e a t 
 *
 **************************************
 *
 * Functional description
 *	Execute a REPEAT statement.  In short, loop.
 *
 **************************************/
	SLONG count;

	count = MOVQ_get_long(EVAL_value(node->nod_arg[e_rpt_value]), 0);

	while (--count >= 0)
		EXEC_execute(node->nod_arg[e_rpt_statement]);
}


static void execute_store( QLI_NOD node)
{
/**************************************
 *
 *	e x e c u t e _ s t o r e
 *
 **************************************
 *
 * Functional description
 *	Execute a STORE statement.  This may involve starting
 *	a request, sending a message, and executing a sub-statement.
 *	On the other hand, it may be a mody no-op if the statement
 *	is part of another request and doesn't need any data from
 *	here.
 *
 **************************************/
	QLI_REQ request;
	QLI_MSG message;

	if (message = (QLI_MSG) node->nod_arg[e_sto_send])
		set_null(message);

	if (!(node->nod_flags & NOD_remote))
		EXEC_execute(node->nod_arg[e_sto_statement]);

/* If there is a request associated  with the node, start it and possibly
   send a message along with it. */

	if (request = (QLI_REQ) node->nod_arg[e_sto_request])
		EXEC_start_request(request, (QLI_MSG) node->nod_arg[e_sto_send]);
	else if (message)
		EXEC_send(message);

	if (QLI_count)
		print_counts(request);
}


static void map_data( QLI_MSG message)
{
/**************************************
 *
 *	m a p _ d a t a
 *
 **************************************
 *
 * Functional description
 *	Map data to a message in preparation for sending.
 *
 **************************************/
	PAR parameter, missing_parameter;
	QLI_NOD from;
	DSC *desc;
	USHORT *missing_flag;

	for (parameter = message->msg_parameters; parameter;
		 parameter = parameter->par_next) {
		desc = &parameter->par_desc;
		desc->dsc_address = message->msg_buffer + parameter->par_offset;
		if (missing_parameter = parameter->par_missing) {
			missing_flag =
				(USHORT *) (message->msg_buffer +
							missing_parameter->par_offset);
			*missing_flag =
				(desc->dsc_missing & DSC_missing) ? DSC_missing : 0;
		}

		from = parameter->par_value;
		if (desc->dsc_dtype == dtype_blob && copy_blob(from, parameter))
			continue;
		assignment(from, desc, 0, 0, parameter->par_missing);
	}
}


static void print_counts( QLI_REQ request)
{
/**************************************
 *
 *	p r i n t _ c o u n t s
 *
 **************************************
 *
 * Functional description
 *	Print out the count of records affected 
 *	by the last statement.
 *
 **************************************/
	UCHAR item;
	int length;
	ULONG number;
	ISC_STATUS status_vector[ISC_STATUS_LENGTH];
	SCHAR count_buffer[COUNT_ITEMS * 7 + 1], *c;

	if (gds__request_info(status_vector,
						  GDS_REF(request->req_handle),
						  0,
						  sizeof(count_info),
						  count_info,
						  sizeof(count_buffer), count_buffer)) return;

/* print out the counts of any records affected */

	for (c = count_buffer; *c != gds_info_end; c += length) {
		item = *c++;
		length = gds__vax_integer((UCHAR*) c, 2);
		c += 2;
		number = gds__vax_integer((UCHAR*) c, length);

		if (number)
			switch (item) {
			case gds_info_req_select_count:
				ib_printf("\nrecords selected: %ld\n", number);
				break;

			case gds_info_req_insert_count:
				ib_printf("records inserted: %ld\n", number);
				break;

			case gds_info_req_update_count:
				ib_printf("records updated: %ld\n", number);
				break;

			case gds_info_req_delete_count:
				ib_printf("records deleted: %ld\n", number);
				break;

			default:
				return;
			}
	}
}


static void set_null( QLI_MSG message)
{
/**************************************
 *
 *	s e t _ n u l l
 *
 **************************************
 *
 * Functional description
 *	Set all parameters of an outgoing
 *	message to null - this allows conditional
 *	assignments to work in store and modify
 *	statements.
 *
 **************************************/
	PAR parameter;
	QLI_NOD from;
	DSC *desc;

	for (parameter = message->msg_parameters; parameter;
		 parameter = parameter->par_next) {
		from = parameter->par_value;
		if (from->nod_type == nod_field) {
			desc = EVAL_value(from);
			desc->dsc_missing |= DSC_missing;
		}
		else
			from->nod_desc.dsc_missing |= DSC_missing;
	}
}



static void transaction_state( QLI_NOD node, DBB database)
{
/**************************************
 *
 *	t r a n s a c t i o n _ s t a t e
 *
 **************************************
 *
 * Functional description
 *	
 *	set the state of the working transaction
 *	in a particular database to prepared or
 *	committed.
 *
 **************************************/
	ISC_STATUS status[ISC_STATUS_LENGTH];

	if (database->dbb_transaction) {
		if (node->nod_type == nod_commit_retaining) {
			if (gds__commit_retaining(status,
									  GDS_REF(database->dbb_transaction)))
					ERRQ_database_error(database, status);
		}
		else if (node->nod_type == nod_prepare) {
			if (gds__prepare_transaction(status,
										 GDS_REF(database->dbb_transaction)))
					ERRQ_database_error(database, status);
		}
	}
}